Can you be a Christian and not go to church?
Sure you can; but not an effective, knowledgeable one!
The church is more than just anyone that accepts Jesus as Savior.
The church is important to Jesus.
He told Peter, “…on this rock I will build My church.” Matt 16:18
Jesus gave authority to the church; Moreover if your brother sins against you, go and tell him his fault between you and him alone. If he hears you, you have gained your brother. But if he will not hear, take with you one or two more, that ‘by the mouth of two or three witnesses every word may be established.’ And if he refuses to hear them, tell it to the church. But if he refuses even to hear the church, let him be to you like a heathen and a tax collector. Matt 18:15-17
Jesus has a great love for the church; Christ also loved the church and gave Himself for her. Eph 5:25
The church is His body; for the sake of His body, which is the church. Col 1:24
Back to the original question and the effective, knowledgeable Christian; your body could not be effective unless all individual parts are working in the manner they were created to.
Since the church is the body of Christ, we find that as the body is one and has many members, but all the members of that one body , being many, are one body, so also is Christ. For by one Spirit we were all baptized into one body — whether Jews or Greeks, whether slaves or free — and have all been made to drink into one Spirit. For in fact the body is not one member but many. 1 Cor 12:12-14
The church serves the purpose of giving life to the other members of the body.
As iron sharpens iron, so a man sharpens the countenance of his friend. Prov 27:17
In church we sharpen each other in Christian love, encouragement, and prayer.
It is not the going to church that makes you a Christian; it is the going to church that helps you be a better Christian.